DFH - Defacto FreeEMS Hardware in KICAD

[Fred]

It does seem a lot, BUT, my prototype setup which doesn't actually do much uses around 250 or so and could be squeezed onto a 160 x 100 board OK

[jharvey]

Here's freeEMS 1.0 A.12

https://sourceforge.net/project/showfil ... _id=621021

This time I added LED's the the outputs, inversion for RPM inputs and ignition drivers, I also finished selecting footprints. Pending review, it's ready to move to PCB layout.

Is there any other items that should be included? You might be able to tell, I'm eager to move to the next step.

[Fred]

You are a legend mate! But slow down or we'll have beautiful boards and no firmware for them! ;-)

I'd like to take a solid look through before you spend much/any time on PCB design. I'd like Jean and Dave and Delta etc to take a look too.

Fred.

[jharvey]

Alright, on that note, I'll go get some sleep. Keep in mind I'm chomping at the bit, and might not be able to stop myself

[jharvey]

Oh also I've been stripping out the extra redundant pages of the schematic PDF. I'm assuming most folks will have KICAD and that these files will work just fine for them. If anyone wants me to print the full PDF, just say the word, and I'll crank it out.

[Fred]

Alright, on that note, I'll go get some sleep. Keep in mind I'm chomping at the bit, and might not be able to stop myself ;)

Worst case is you have to rework some stuff if it changes... or someone else could etc. etc. You may do as you please, but there are things that need fixing with regards pin out from the CPU that I need to make decisions on, so you should really wait a bit.

[Brian]

I can see some of the LED's wil turn on when the output is off, this may not be the desired outcome.
Also it looks like there is two places where 12V is connected to the 5V regulator output via two resistors R43/R45 and R151/R153. Thanks for doing the pdf.

[jharvey]

I should add some more notes to my schematics. The intent there is that only R43 or R45 be installed. This allows for 5v or 12v operation and allows for me to put the footprint on the PCB. So schematic notes is added to the TODO list. Are there any other places you see that a note might be handy?

Hmm, about 151 and 153. I'm sure I had 151 and 152 in there for a reason, but I can't seem to remember it now. Perhaps these should go?

My thoughts about the LED's was that yes the will light when the FET is off, so how about red LED's for that, then LED's that are on when on, can be green. I couldn't really find a "good" solution for inverting the LED on condition to make them light when in the on state. It always involved putting the LED behind the fet, extra parts, or altering the output current path. I didn't like any of those options, so I made it blink a bit less intuitively.

Keep up the review.

[Fred]

to make leds go on when the fet is on, hook them to 12v, to make them go on when it's off, hook them to ground, however that would require a pull up on the output too depending on what it is the pull up could be the injector or coil etc.

[Fred]

For all the injectors, the fuel pump and the coils the leds should go to 12v just like the device being driven. I didn't look at the schem yet, but that's how it should be. For the inputs the led should be grounded and fed with the same input as the processor post XOR chip. I'll get to the schem later today if things go well.

Fred.